Enhanced E-Beam Evaporation of Tin
Original Publication Date: 1983-Jul-01
Included in the Prior Art Database: 2005-Feb-07
During E-beam evaporation of tin, molten tin splashes under high power and spills onto cooling hearth, cooling down crucible. The objective here is to evaporate tin at a high angstrom per second rate. With the crucible in contact with the copper cooling hearth a much higher rate can be obtained. However, spitting of tin occurs with splash out and shorting of the crucible to the cooling hearth. Spacers between the crucible and the cooling hearth were tried so as to reduce the cooling of the tin. Copper, stainless steel, and molybdenum were tried. Higher evaporation rates could be obtained with both copper and stainless steel, but they eventually reacted and stuck to the bottom of the crucible. Molybdenum works very well and has not stuck to the bottom of the crucible to date. The general design concept is shown in Fig. l.